Dust Grains Could Be Remnants of Stellar Explosions From Billions of Years Ago: Study

Microscopic dust particles found in meteoritic material on the Earth may be particles that were likely formed in stellar explosions that occurred long before the creation of the Sun, researchers report.

The team from Michigan State University (MSU) is investigating whether the particles may have formed in a classical nova - a thermonuclear explosion on the surface of a small star which is part of a binary star system - two stars orbiting each other.

This explosion nearly five billions years ago would have ejected stellar material in the form of gas and dust into the space between stars in the galaxy.

Some of that material would have been used in the creation of our solar system.

"There is a recycling process going on here. When stars die, they spew out material in the form of dust and gas, which then gets recycled into future generations of stars and planets," said Christopher Wrede, assistant professor of physics at the MSU.

To learn more about this five-billion-year old question, Wrede and his team carried out an experiment in which they created and studied the exotic radioactive nuclei that have the greatest influence on the production of silicon isotopes in novae.

It turns out that the grains of stardust contain unusually high amounts of the isotope silicon-30, which is made up of 14 protons and 16 neutrons.

Silicon-30 is quite rare on Earth (the most common is silicon-28). Researchers know that silicon-30 is produced in classical novae, said the paper published in the journal Physical Review Letters.

"These particular grains are potential messengers from classical novae that allow us to study these events in an unconventional way," Wrede added.

The experiment is being conducted at the National Superconducting Cyclotron laboratory at MSU.